In recent years image guided navigation systems utilizing an electromagnetic source and electromagnetic detectors or receivers have been developed for minimally invasive surgical implantation procedures. The source, positioned external to a patient, sets up a magnetic field that induces a voltage in receivers mounted on a surgical instrument or delivery tool, which has been inserted within a body of a patient disposed within the magnetic field. The voltage induced in each receiver is dependent upon a location and orientation of the respective receiver within the magnetic field. By sensing and processing current conducted from each receiver, a navigation analysis system can determine a location of each receiver with respect to one another and provide a visual map to aid an operator in navigating the instrument or tool to a target site within a body of a patient. An example of such an image guided navigation system is described in pre-grant patent publication US 2004/0097806, salient portions of which are hereby incorporated by reference.
If electromagnetic receivers are mounted directly onto a delivery tool, for example a guiding catheter, the receivers may either increase the profile of the tool or take up space within the tool that could otherwise be used to deliver therapeutic elements, for example, a medical device inserted through a lumen of the tool. Thus, it would be desirable to have a modular therapy delivery system wherein a navigation element including electromagnetic receivers can be included in the system for navigation purposes, and then removed from the system to increase system capacity for therapy delivery, for example, to open up a lumen for passage of a medical device therethrough, once the system has been navigated to an appropriate site. It would be further desirable that such a navigation element be constructed for maximum durability and to accommodate additional modules of the modular system.